Background and Purpose: Rates of high quality recanalization after endovascular thrombectomy in acute ischemic stroke are excellent, but not all vessels are easily or quickly recanalized. Physical characteristics of the occlusion may affect recanalization. The hyper-dense vessel sign (HDVS) is an easily obtained marker of clot density and was hypothesized to predict success of recanalization.
Methods: A prospectively maintained database of patients undergoing mechanical thrombectomy was retrospectively analyzed. The final quality of recanalization was scored by the treating interventionalist. The presence or absence of HDVS was scored blinded. HDVS was defined as an absolute HU >43 and ratio versus contralateral vessel of >1.2 on non-contrast head CT.
Results: 408 patients were treated with endovascular thrombectomy between August 2012 to July 2015. Mean age was 67.7. 53% were men. Mean NIHSS was 17. 88% were MCA occlusions and 11% were basilar occlusions. Mean ASPECT was 8.6 for MCA occlusions. 90.6% of patients were successfully revascularized with TICI2b/3. HDVS was identified in 43.3% of patients. 40.5% of patients had TICI2b/3 reperfusion after the first pass of attempted thrombectomy. Manual aspiration thrombectomy was the first technique in 45.6% and stentreiver mediated manual aspiration thrombectomy was used first in 54.4% of cases. Of 357 attempted MCA thrombectomies, 43.3% had a HDVS. Of 44 attempted basilar thrombectomies, 56.7% had a HDVS. TICI 2b/3 reperfusion on first-pass was associated with absence of HDVS (p=0.001). Time from puncture to reperfusion was significantly increased with HDVS (p=0.003).
Conclusion: Patients with a hyper-dense vessel sign have less successful first-pass revascularization with increased times to reperfusion versus patients without a hyper-dense vessel sign. The presence of HDVS may be indicative of more refractory occlusions and may warrant novel and multimodal methods of revascularization.